NASA has discovered a nearby planetary system is says is ‘remarkably similiar’ to our own.
Located 10.5 light-years away in the southern hemisphere of the constellation Eridanus, the star Epsilon Eridani, eps Eri for short, is the closest planetary system around a star similar to the early sun.
It is a prime location to research how planets form around stars like our sun, and is also the storied location of the Babylon 5 space station in the science fictional television series of the same name.
NASA’s flying observatory, the Stratospheric Observatory for Infrared Astronomy, SOFIA, made the discovery.
Previous studies indicate that eps Eri has a debris disk, which is the name astronomers give to leftover material still orbiting a star after planetary construction has completed.
The debris can take the form of gas and dust, as well as small rocky and icy bodies.
Debris disks can be broad, continuous disks or concentrated into belts of debris, similar to our solar system’s asteroid belt and the Kuiper Belt – the region beyond Neptune where hundreds of thousands of icy-rocky objects reside.
Furthermore, careful measurements of the motion of eps Eri indicates that a planet with nearly the same mass as Jupiter circles the star at a distance comparable to Jupiter’s distance from the Sun.
Iowa State University’s Massimo Marengo said the findings are important because they confirm epsilon Eridani is a good model of the early days of our solar system and can provide hints at how our solar system evolved.
‘This star hosts a planetary system currently undergoing the same cataclysmic processes that happened to the solar system in its youth, at the time in which the moon gained most of its craters, Earth acquired the water in its oceans, and the conditions favorable for life on our planet were set,’ Marengo wrote in a summary of the project.
Determining the structure of the disk was a complex effort that took several years and detailed computer modeling.
The astronomers had to separate the faint emission of the disk from the much brighter light coming from the star.
‘But we can now say with great confidence that there is a separation between the star’s inner and outer belts,’ Marengo said.
‘We haven’t detected them yet, but I would be surprised if they are not there. Seeing them will require using the next-generation instrumentation, perhaps NASA’s 6.5-meter James Webb Space Telescope scheduled for launch in October 2018.’
‘The prize at the end of this road is to understand the true structure of epsilon Eridani’s out-of-this-world disk, and its interactions with the cohort of planets likely inhabiting its system,’ Marengo wrote in a newsletter story about the project.
‘SOFIA, by its unique ability of capturing infrared light in the dry stratospheric sky, is the closest we have to a time machine, revealing a glimpse of Earth’s ancient past by observing the present of a nearby young sun.’
With the new SOFIA images, Kate Su of the University of Arizona and her research team were also able to distinguish between two theoretical models of the location of warm debris, such as dust and gas, in the eps Eri system.
These models were based on prior data obtained with NASA’s Spitzer space telescope.
One model indicates that warm material is in two narrow rings of debris, which would correspond respectively to the positions of the asteroid belt and the orbit of Uranus in our solar system.
Using this model, theorists indicate that the largest planet in a planetary system might normally be associated with an adjacent debris belt.
The other model attributes the warm material to dust originating in the outer Kuiper-Belt-like zone and filling in a disk of debris toward the central star.
In this model, the warm material is in a broad disk, and is not concentrated into asteroid belt-like rings nor is it associated with any planets in the inner region.
Using SOFIA, Su and her team ascertained that the warm material around eps Eri is in fact arranged like the first model suggests; it is in at least one narrow belt rather than in a broad continuous disk.